In the study, 21 people rated more than 80 taste combinations. From this data, the researchers found that astringents and greasy food balance each other out well: Astringents leave the mouth feeling dry and rough, while fatty food leave the mouth feeling unpleasantly slippery.

Without this pairing neither food was as enjoyable. When the subjects had greasy food and water, there was an unpleasant fatty and slipperiness in their mouths. On the other hand, when they took in astringent foods, which break down lubricating proteins in saliva, their mouths felt dry and rough.